Clarksville is a town in Clark County, Indiana, United States, along the Ohio River as a part of the Louisville Metropolitan area. The population was 21,724 at the 2010 census. The town, once a home site to George Rogers Clark, was founded in 1783 and is the oldest American town in the Northwest Territory. The town is home to the Colgate clock, one of the largest clocks in the world and the Falls of the Ohio State Park, a large fossil bed.
Clarksville is named for American Revolutionary War General George Rogers Clark, who lived for a time on a point of land on the Ohio River. Founded in 1783, the town is believed to be the first American settlement in the Northwest Territory of the new United States.
The site was first used as a base of operations by Clark during the American Revolution. In 1778 he established a post on an island at the head of the Falls of the Ohio. From there he trained his 175-man regiment for the defense to the west. After the war, Clark was granted a tract of 150,000 acres (610 km2) for his services in the war. In 1783 1,000 acres (4 km2) were set aside for the development of a town, Clarksville. The same year a stockade was built and settlement began.